1.0. Field of the Invention
The present invention relates to a computer-implemented method, system and computer program product for backing up and recovering a database.
2.0. Description of the Related Art
Computer systems and databases have been used in key businesses of companies and their importance to company operations has increased rapidly. Thus, there is a demand for hardware and techniques that can efficiently back up the contents of a database to prepare for the occurrence of system malfunctions or disasters, and that will not interrupt or otherwise adversely affect normal operations while performing the backup process. To satisfy such a demand, it is desirable to backup a database quickly.
In some current conventional storage systems, such as Storage Area Network (SAN) and Network Attached Storage (NOS), storage devices may have a volume copy function for copying the contents stored on the storage devices at high speed. For example, a technique has been proposed in which each time data are updated they are stored in a plurality of storage devices by mirroring one of which will used as a backup at a desired time (see Japanese Published Patent Application JP2002-082826).
A backup process may generate a backup at high speed by utilizing a volume copy function. However, a recent database may be stored, part-by-part, in a plurality of storage devices in order to increase processing speed and distribute the processing load. In addition, a single storage device may store respective portions of several databases in order to efficiently use storage areas.
Thus, if the volume copy function is directly employed, data unnecessary for the generation of a backup may be copied, or the data for the generation of a backup may be insufficient. Furthermore, to maintain consistency, a backup of a database should be generated after a transaction on the database is completed. If volume copying is simply performed for each storage device, a backup might be generated without maintaining the consistency for the entire database. Therefore, there is a need for an improved technique to backup a database.